Peter Messervy-Gross, from St Ouen, Jersey, clambered across sheets of ice wearing his four-year-old work shoes – suffering agonising blisters in the process.

He was taking part in an extreme new adventure race, called the ‘Mongol 100’, brainchild of UK firm Rat Race Adventure Sports.

Vast lake ‘Khövsgöl Nuur’, located in northern Mongolia, freezes every winter and last week saw dozens of participants walk, run or skate a bone-chilling 100 miles across it.

Dad-of-three Peter spent five months researching what “shiny new kit” to buy to complete the feat – in which his competitors wore cutting edge winter walking boots, ice skates or other technical footwear.

But his heart sank when he realised he would be forcing his freezing feet into his trusty, battered ‘Joules’ leather brogues – for 10 hours a day in temperatures down to minus -25 degrees C.

He says he also turned into a ‘walking charity shop’ as fellow competitors desperately tried to lend him kit!

The 47-year-old, who flew from Heathrow Airport to Mongolia’s capital Ulaanbaatar with Russian airline Aeroflot, said: “When we arrived in Mongolia my large holdall was missing but everyone seemed pretty confident it would turn up, so I wasn’t worried.

“At that point we had two days until race day.”

Jim Mee, the Rat Race founder, suggested Peter buy some technical shoes, just in case.

However, according to Peter, you can’t buy shoes larger than a size 11 in Mongolia – and he is a size 13.

And when he arrived in Murun, home to a tiny rural airport that sits near the southern tip of Khövsgöl Nuur, it dawned on Peter he’d have to complete the race in the clothes he arrived in!

The chief information officer for global administration firm Sanne says: “It was a heartbreaking moment for me, very gutting, because you can’t really run 100 miles across a frozen lake in brogues!

“I had a toothbrush on me but no deodorant, toilet roll, soap or wipes.

“But the other competitors were amazing, offering up stuff for me to use, which was incredible because it meant by giving things to me, they were worse off.

“My friend Marcus gave me a set of thermals, another guy gave me some socks, someone else handed me a balaclava – and I was a walking charity shop!”

Competitors battled through marathon-distance stages on each of the four days that the challenge took place.

Some competitors dropped out of the race through a mixture of injury, fatigue and cold – but Peter kept going – despite his feet swelling up.

He adds: “When you run a race like that your feet swell because you’re on them for so long – I literally became too big for my boots.

“It did get pretty uncomfortable, my feet blistered really badly and especially on my little toes, which was quite painful.

“But I just wanted to keep plodding along – I couldn’t really feel the cold in my feet during the day, it was more discomfort than anything else.”

Peter says the group found the scale of the place “phenomenal”.

“You look around and as far as you can see there’s just sheets of ice,” he adds.

“It cracks under your feet and you can hear it booming as it breaks up in the distance.”

Peter and his pal Marcus Liddiard, 43, hadspent five months training for the event.

And Peter explains: “My emotions were all over the place during the challenge.

“I experienced the highest highs, whooping, hugging and high-fiving people – and the lowest lows, when I was alone, spent and shedding tears because of how tough it was.

“If the sun went behind a cloud, the wind came up or it was reaching sunset, the temperature just absolutely plummeted and it was freezing cold.

“Walking in my jeans and brogues wasn’t exactly what I had in mind, but I didn’t want to give up or hold Marcus back.

“When I crossed that finish line I was elated.

“I genuinely didn’t think I was going to be able to do the whole thing without my kit – maybe just a little bit of day one or something.

“My shoes held up surprisingly well – I’m just a bit allergic to putting the things on now!

“We were at the airport the following day after finishing the event – and my luggage turned up 15 minutes before check-in for our return home…’

The cost of entry to the Mongol 100 is £2,500 per person – and registration is already open for next year, with the event due to take place from March 1-8, 2020.